PayPal (EBAY) acquires Iron Pearl, a startup developing software that aims to boost customer retention by analyzing user activity. Presumably, PayPal wants to use Iron Pearl's to uncover ways too increase transaction volumes among existing users. In a blog post, PayPal chief David Marcus (previous) praises Iron Pearl for developing "groundbreaking tools, methodologies and intellectual property, built on a new understanding of the social and cultural factors that drive the viral spread of products, combined with new approaches to data analysis and predictive modeling"